The present invention relates to a tongue assembly for use in a safety apparatus having a belt for restraining movement of an occupant of a vehicle.
Many known vehicle safety systems have a tongue assembly which is used to connect a belt with a buckle in order to restrain movement of an occupant of the vehicle. The tongue assembly must be capable of transmitting relatively large forces in order to restrain an occupant of the vehicle against movement in the event of a sudden deceleration of the vehicle. The tongue assembly should also be thin to minimize interference with the occupant of the vehicle. In addition to being capable of transmitting large forces and being thin, the tongue assembly should be easy to manufacture in order to minimize the cost of making the tongue assembly.
When the tongue assembly is released from the buckle, the belt is wound onto a retractor. As the belt is wound onto the retractor, both the belt and the tongue assembly are moved by the retractor. Since both the belt and tongue assembly are moved by the retractor, the retractor must have a relatively strong wind-up spring. The wind-up spring must be capable of exerting enough force on the belt to move the combined weight of the belt and the tongue assembly. When the belt is in use, the relatively large force exerted by the retractor wind-up spring results in the belt being pulled across the torso of an occupant of the vehicle with a force which the occupant may find to be objectionably large.